This　paper　presents　a　systematic　study　on　the　evolution　of　phase　composition,　microstructure　and　micro　-mechanical　properties　of　magnesium　phosphate　cement　(MPC)　and　their　relations　to　macroscopic　mechanical　properties.　The　results　indicate　that　the　microstructure　of　MPC　is　mainly　composed　of　a　crystal　region　of　po-tassium　magnesium　phosphate　hexahydrate　(MKP)　and　a　hybrid　region　of　magnesium　oxide　and　amorphous　hydration　products.　The　elastic　modulus　and　hardness　of　MKP　crystals　are　20.18　GPa　and　1.15　GPa,　respectively.　Amorphous　hydration　products　may　consist　of　MgKPO4　and　Mg3　(PO4)2.　The　elastic　modulus　of　amorphous　MgKPO4　drops　gradually　from　51.4　GPa　to　29.2　GPa　with　increasing　curing　age　towards　the　elastic　modulus　of　crystalline　MKP,　while　the　elastic　moduli　of　amorphous　Mg3(PO4)2　and　unreacted　MgO　are　approximately　160　GPa　and　300　GPa,　respectively.　The　macroscopic　strength　of　MPC　is　mainly　dependent　on　its　pore　structure　rather　than　the　micromechanical　properties　of　hydration　products.